edu.ucar.opensky::articles:10310 UCAR/NCAR - Library OpenSky Support PO Box 3000 Boulder CO 80307-3000 opensky@ucar.edu http://opensky.ucar.edu/ homepage pointOfContact 2025-12-26T14:50:52.961425 ISO 19115-2 Geographic Information - Metadata - Part 2: Extensions for Imagery and Gridded Data ISO 19115-2:2009(E) https://n2t.org/ark:/85065/d7rj4jxq Observational constraints on the global atmospheric budget of ethanol 2010-06-17T00:00:00Z publication https://n2t.org/ark:/85065/d7rj4jxq https://doi.org/10.5194/acp-10-5361-2010 Naik, V. author Fiore, A. author Horowitz, L. author Singh, H. author Wiedinmyer, Christine author Guenther, Alex B. author De Gouw, J. author Millet, D. author Goldan, P. author Kuster, W. author Goldstein, A. author UCAR/NCAR - Library publisher Energy security and climate change concerns have led to the promotion of biomass-derived ethanol, an oxygenated volatile organic compound (OVOC), as a substitute for fossil fuels. Although ethanol is ubiquitous in the troposphere, our knowledge of its current atmospheric budget and distribution is limited. Here, for the first time we use a global chemical transport model in conjunction with atmospheric observations to place constraints on the ethanol budget, noting that additional measurements of ethanol (and its precursors) are still needed to enhance confidence in our estimated budget. Global sources of ethanol in the model include 5.0 Tg yr⁻¹ from industrial sources and biofuels, 9.2 Tg yr⁻¹ from terrestrial plants, ~0.5 Tg yr⁻¹ from biomass burning, and 0.05 Tg yr⁻¹ from atmospheric reactions of the ethyl peroxy radical (C₂H₅O₂) with itself and with the methyl peroxy radical (CH₃O₂). The resulting atmospheric lifetime of ethanol in the model is 2.8 days. Gas-phase oxidation by the hydroxyl radical (OH) is the primary global sink of ethanol in the model (65%), followed by dry deposition (25%), and wet deposition (10%). Over continental areas, ethanol concentrations predominantly reflect direct anthropogenic and biogenic emission sources. Uncertainty in the biogenic ethanol emissions, estimated at a factor of three, may contribute to the 50% model underestimate of observations in the North American boundary layer. Current levels of ethanol measured in remote regions are an order of magnitude larger than those in the model, suggesting a major gap in understanding. Stronger constraints on the budget and distribution of ethanol and OVOCs are a critical step towards assessing the impacts of increasing the use of ethanol as a fuel. UCAR/NCAR - Library OpenSky Support PO Box 3000 Boulder CO 80307-3000 opensky@ucar.edu http://opensky.ucar.edu/ homepage pointOfContact PDF Text theme Resource Type 2016-01-01T00:00:00Z publication Copyright Author(s) 2010. This work is distributed under the Creative Commons Attribution 3.0 License. None eng geoscientificInformation